Hand-held calculators having a nine, ten, or eleven digit display have been in common use for a number of years. Recently, computers or microprocessors having a keyboard of the type found in an ordinary typewriter, and a minimum display capacity, have been marketed. These microprocessors generally have a display capacity of sixteen to eighty characters, and are generally of the size of a pad of paper, that is, 8".times.11".times.3/4" (20.3.times.28.times.2 cm). These "tablet size" microprocessors may include provision for a storage medium such as a cassette or the like. This type of microprocessor, in one form, may be used as a word processor, while in other forms it can be used as a small computer capable of storing data files, each comprised of a number of records. An example of one of these microprocessors is available from Hewlett-Packard Company, Palo Alto, Calif. as Model HP-75c. The problem presented to the user of such a microprocessor is that the entire record generally exceeds the display capacity. Thus, the record length may be, for example, eighty or one hundred characters long, and in order to display the entire record, the user must call up segments of the record divisible by the length of the display device. Thus, in the example just given, a record of ninety characters in length would require at least three "looks" to be fully displayed to the user. Therefore, in "leafing through" a file, the user must look at each record, or at least portions of each record, three times.
Quite frequently, the data contained in a particular record may be of little use in one particular "look-up", while at another time that same data would be extremely pertinent. This is particularly true when the user is updating fields in a record.
For example, if a hand-held computer were to be used as an address file, or more particularly, a personnel file, it may be that at one time the user would be desirous of obtaining an individual's phone number, while the next time, the user would be desirous of obtaining the name of the individual's employer. Thus, in the file described above having ninety characters in each record, the user, in the first case, would have no need for information relating to "employer" but would be interested in the employee's name and telephone number. In the second instance, the user would not be interested in the telephone number, but rather would be interested in the employer.
Current data file display programs are generally adaptable through programming for use on fixed cathode ray tubes having a relatively large display capability. Thus, entire records or multiple fields are relatively easily displayed by utilizing two or more lines of the cathode ray tube. Even with a CRT, the user or designer is forced to specify a maximum width for each field type. Generally, the full field width is displayed, leaving blank spaces. In the small hand-held environment, the luxury of large display devices is not available. However, it is still necessary to identify relatively easily each record as it is called up.
It is an object of this invention to provide a capability in a microprocessor to reduce data fields to fit into a limited display area, and selectively to increase the size of a particular data field to utilize extra space that may be available.
It is also a primary object of this invention to display in a series of reduced fields a full-length field along with the data field name that has been selected by the user.
It is a further object of this invention to ensure that the above objects are met even though the underlying fields are of undetermined length.
It is a still further object of this invention to provide to the user a visual image of the record so that the various fields in the record are readily recognizable.